The growing research toolbox for SLC13A5 citrate transporter disorder: a rare disease with animal models, cell lines, an ongoing Natural History Study and an engaged patient advocacy organization
Brown TL, Bainbridge MN, Zahn G, Nye KL, Porter BE.
Ther Adv Rare Dis. 2024 Jul 31;5:26330040241263972. doi: 10.1177/26330040241263972. eCollection 2024 Jan-Dec.
ABSTRACT
TESS Research Foundation (TESS) is a patient-led nonprofit organization seeking to understand the basic biology and clinical impact of pathogenic variants in the SLC13A5 gene. TESS aims to improve the fundamental understanding of citrate’s role in the brain, and ultimately identify treatments and cures for the associated disease. TESS identifies, organizes, and develops collaboration between researchers, patients, clinicians, and the pharmaceutical industry to improve the lives of those suffering from SLC13A5 citrate transport disorder. TESS and its partners have developed multiple molecular tools, cellular and animal models, and taken the first steps toward drug discovery and development for this disease. However, much remains to be done to improve our understanding of the disorder associated with SLC13A5 variants and identify effective treatments for this devastating disease. Here, we describe the available SLC13A5 resources from the community of experts, to foundational tools, to in vivo and in vitro tools, and discuss unanswered research questions needed to move closer to a cure.
PMID:
39091896 | PMC:
PMC11292725 | DOI:
10.1177/26330040241263972
July 31, 2024
Rare Disease
MSL2 variants lead to a neurodevelopmental syndrome with lack of coordination, epilepsy, specific dysmorphisms, and a distinct episignature
Karayol R, Borroto MC, Haghshenas S, Namasivayam A, Reilly J, Levy MA, Relator R, Kerkhof J, McConkey H, Shvedunova M, Petersen AK, Magnussen K, Zweier C, Vasileiou G, Reis A, Savatt JM, Mulligan MR, Bicknell LS, Poke G, Abu-El-Haija A, Duis J, Hannig V, Srivastava S, Barkoudah E, Hauser NS, van den Born M, Hamiel U, Henig N, Baris Feldman H, McKee S, Krapels IPC, Lei Y, Todorova A, Yordanova R, Atemin S, Rogac M, McConnell V, Chassevent A, Barañano KW, Shashi V, Sullivan JA, Peron A, Iascone M, Canevini MP, Friedman J, Reyes IA, Kierstein J, Shen JJ, Ahmed FN, Mao X, Almoguera B, Blanco-Kelly F, Platzer K, Treu AB, Quilichini J, Bourgois A, Chatron N, Januel L, Rougeot C, Carere DA, Monaghan KG, Rousseau J, Myers KA, Sadikovic B, Akhtar A, Campeau PM.
Am J Hum Genet. 2024 May 28:S0002-9297(24)00164-2. doi: 10.1016/j.ajhg.2024.05.001. Online ahead of print.
ABSTRACT
Epigenetic dysregulation has emerged as an important etiological mechanism of neurodevelopmental disorders (NDDs). Pathogenic variation in epigenetic regulators can impair deposition of histone post-translational modifications leading to aberrant spatiotemporal gene expression during neurodevelopment. The male-specific lethal (MSL) complex is a prominent multi-subunit epigenetic regulator of gene expression and is responsible for histone 4 lysine 16 acetylation (H4K16ac). Using exome sequencing, here we identify a cohort of 25 individuals with heterozygous de novo variants in MSL complex member MSL2. MSL2 variants were associated with NDD phenotypes including global developmental delay, intellectual disability, hypotonia, and motor issues such as coordination problems, feeding difficulties, and gait disturbance. Dysmorphisms and behavioral and/or psychiatric conditions, including autism spectrum disorder, and to a lesser extent, seizures, connective tissue disease signs, sleep disturbance, vision problems, and other organ anomalies, were observed in affected individuals. As a molecular biomarker, a sensitive and specific DNA methylation episignature has been established. Induced pluripotent stem cells (iPSCs) derived from three members of our cohort exhibited reduced MSL2 levels. Remarkably, while NDD-associated variants in two other members of the MSL complex (MOF and MSL3) result in reduced H4K16ac, global H4K16ac levels are unchanged in iPSCs with MSL2 variants. Regardless, MSL2 variants altered the expression of MSL2 targets in iPSCs and upon their differentiation to early germ layers. Our study defines an MSL2-related disorder as an NDD with distinguishable clinical features, a specific blood DNA episignature, and a distinct, MSL2-specific molecular etiology compared to other MSL complex-related disorders.
PMID:
38815585 | DOI:
10.1016/j.ajhg.2024.05.001
July 11, 2024
Genetic Neurologic Disease
Biallelic Loss of Function Variants in SENP7 Cause Immunodeficiency with Neurologic and Muscular Phenotypes
Kobayashi ES, Lotan NS, Schejter YD, Makowski C, Kraus V, Ramchandar N, Meiner V, Thiffault I, Farrow E, Cakici J, Kingsmore S, Wagner M, Rieber N, Bainbridge M.
J Pediatr. 2024 Jul 4:114180. doi: 10.1016/j.jpeds.2024.114180. Online ahead of print.
ABSTRACT
To evaluate a novel candidate disease gene, we engaged international collaborators and identified rare, biallelic, specifically homozygous, loss of function variants in SENP7 in four children from three unrelated families presenting with neurodevelopmental abnormalities, dysmorphism, and immunodeficiency. Their clinical presentations were characterized by hypogammaglobulinemia, intermittent neutropenia, and ultimately death in infancy for all four patients. SENP7 is a sentrin-specific protease involved in posttranslational modification of proteins essential for cell regulation, via a process referred to as deSUMOylation. We propose that deficiency of deSUMOylation may represent a novel mechanism of primary immunodeficiency.
PMID:
38972567 | DOI:
10.1016/j.jpeds.2024.114180
July 5, 2024
Rare Disease
Genome Sequencing for Diagnosing Rare Diseases
Wojcik MH, Lemire G, Berger E, Zaki MS, Wissmann M, Win W, White SM, Weisburd B, Wieczorek D, Waddell LB, Verboon JM, VanNoy GE, Töpf A, Tan TY, Syrbe S, Strehlow V, Straub V, Stenton SL, Snow H, Singer-Berk M, Silver J, Shril S, Seaby EG, Schneider R, Sankaran VG, Sanchis-Juan A, Russell KA, Reinson K, Ravenscroft G, Radtke M, Popp D, Polster T, Platzer K, Pierce EA, Place EM, Pajusalu S, Pais L, Õunap K, Osei-Owusu I, Opperman H, Okur V, Oja KT, O’Leary M, O’Heir E, Morel CF, Merkenschlager A, Marchant RG, Mangilog BE, Madden JA, MacArthur D, Lovgren A, Lerner-Ellis JP, Lin J, Laing N, Hildebrandt F, Hentschel J, Groopman E, Goodrich J, Gleeson JG, Ghaoui R, Genetti CA, Gburek-Augustat J, Gazda HT, Ganesh VS, Ganapathi M, Gallacher L, Fu JM, Evangelista E, England E, Donkervoort S, DiTroia S, Cooper ST, Chung WK, Christodoulou J, Chao KR, Cato LD, Bujakowska KM, Bryen SJ, Brand H, Bönnemann CG, Beggs AH, Baxter SM, Bartolomaeus T, Agrawal PB, Talkowski M, Austin-Tse C, Abou Jamra R, Rehm HL, O’Donnell-Luria A.
N Engl J Med. 2024 Jun 6;390(21):1985-1997. doi: 10.1056/NEJMoa2314761.
ABSTRACT
BACKGROUND: Genetic variants that cause rare disorders may remain elusive even after expansive testing, such as exome sequencing. The diagnostic yield of genome sequencing, particularly after a negative evaluation, remains poorly defined.
METHODS: We sequenced and analyzed the genomes of families with diverse phenotypes who were suspected to have a rare monogenic disease and for whom genetic testing had not revealed a diagnosis, as well as the genomes of a replication cohort at an independent clinical center.
RESULTS: We sequenced the genomes of 822 families (744 in the initial cohort and 78 in the replication cohort) and made a molecular diagnosis in 218 of 744 families (29.3%). Of the 218 families, 61 (28.0%) – 8.2% of families in the initial cohort – had variants that required genome sequencing for identification, including coding variants, intronic variants, small structural variants, copy-neutral inversions, complex rearrangements, and tandem repeat expansions. Most families in which a molecular diagnosis was made after previous nondiagnostic exome sequencing (63.5%) had variants that could be detected by reanalysis of the exome-sequence data (53.4%) or by additional analytic methods, such as copy-number variant calling, to exome-sequence data (10.8%). We obtained similar results in the replication cohort: in 33% of the families in which a molecular diagnosis was made, or 8% of the cohort, genome sequencing was required, which showed the applicability of these findings to both research and clinical environments.
CONCLUSIONS: The diagnostic yield of genome sequencing in a large, diverse research cohort and in a small clinical cohort of persons who had previously undergone genetic testing was approximately 8% and included several types of pathogenic variation that had not previously been detected by means of exome sequencing or other techniques. (Funded by the National Human Genome Research Institute and others.).
PMID:
38838312 | DOI:
10.1056/NEJMoa2314761
June 6, 2024
NeurogenomicsRare Disease
Frontiers in congenital disorders of glycosylation consortium, a cross-sectional study report at year 5 of 280 individuals in the natural history cohort
Lam C, Scaglia F, Berry GT, Larson A, Sarafoglou K, Andersson HC, Sklirou E, Tan QKG, Starosta RT, Sadek M, Wolfe L, Horikoshi S, Ali M, Barone R, Campbell T, Chang IJ, Coles K, Cook E, Eklund EA, Engelhardt NM, Freeman M, Friedman J, Fu DYT, Botzo G, Rawls B, Hernandez C, Johnsen C, Keller K, Kramer S, Kuschel B, Leshinski A, Martinez-Duncker I, Mazza GL, Mercimek-Andrews S, Miller BS, Muthusamy K, Neira J, Patterson MC, Pogorelc N, Powers LN, Ramey E, Reinhart M, Squire A, Thies J, Vockley J, Vreugdenhil H, Witters P, Youbi M, Zeighami A, Zemet R, Edmondson AC, Morava E.
Mol Genet Metab. 2024 Jun 6;142(4):108509. doi: 10.1016/j.ymgme.2024.108509. Online ahead of print.
ABSTRACT
OBJECTIVE: Our report describes clinical, genetic, and biochemical features of participants with a molecularly confirmed congenital disorder of glycosylation (CDG) enrolled in the Frontiers in Congenital Disorders of Glycosylation (FCDGC) Natural History cohort at year 5 of the study.
METHODS: We enrolled individuals with a known or suspected CDG into the FCDGC Natural History Study, a multicenter prospective and retrospective natural history study of all genetic causes of CDG. We conducted a cross-sectional analysis of baseline study visit data from participants with confirmed CDG who were consented into the FCDGC Natural History Study (5U54NS115198) from October 2019 to November 2023.
RESULTS: Three hundred thirty-three subjects consented to the FCDGC Natural History Study. Of these, 280 unique individuals had genetic data available that was consistent with a diagnosis of CDG. These 280 individuals were enrolled into the study between October 8, 2019 and November 29, 2023. One hundred forty-one (50.4%) were female, and 139 (49.6%) were male. Mean and median age at enrollment was 10.1 and 6.5 years, respectively, with a range of 0.22 to 71.4 years. The cohort encompassed individuals with disorders of N-linked protein glycosylation (57%), glycosylphosphatidylinositol anchor disorder (GPI anchor) (15%), disorders of Golgi homeostasis, trafficking and transport (12%), dolichol metabolism disorders (5%), disorders of multiple pathways (6%), and other (5%). The most frequent presenting symptom(s) leading to diagnosis were developmental delay/disability (77%), followed by hypotonia (56%) and feeding difficulties (42%). Mean and median time between first related symptom and diagnosis was 2.7 and 0.8 years, respectively. One hundred percent of individuals in our cohort had developmental differences/disabilities at the time of their baseline visit, followed by 97% with neurologic involvement, 91% with gastrointestinal (GI)/liver involvement, and 88% with musculoskeletal involvement. Severity of disease in individuals was scored on the Nijmegen Progression CDG Rating Scale (NPCRS) with 27% of scores categorized as mild, 44% moderate, and 29% severe. Of the individuals with N-linked protein glycosylation defects, 83% of those with data showed a type 1 pattern on carbohydrate deficient transferrin (CDT) analysis including 82/84 individuals with PMM2-CDG, 6% a type 2 pattern, 1% both type 1 and type 2 pattern and 10% a normal or nonspecific pattern. One hundred percent of individuals with Golgi homeostasis and trafficking defects with data showed a type 2 pattern on CDT analysis, while Golgi transport defect showed a type II pattern 73% of the time, a type 1 pattern for 7%, and 20% had a normal or nonspecific pattern. Most of the variants documented were classified as pathogenic or likely pathogenic using ACMG criteria. For the majority of the variants, the predicted molecular consequence was missense followed by nonsense and splice site, and the majority of the diagnoses are inherited in an autosomal recessive pattern but with disorders of all major nuclear inheritance included.
DISCUSSION: The FCDGC Natural History Study serves as an important resource to build future research studies, improve clinical care, and prepare for clinical trial readiness. Herein is the first overview of CDG participants of the FCDGC Natural History Study.
PMID:
38959600 | DOI:
10.1016/j.ymgme.2024.108509
June 6, 2024
Neurogenomics
Rapid Whole-Genome Sequencing and Clinical Management in the PICU: A Multicenter Cohort, 2016-2023
Rodriguez KM, Vaught J, Salz L, Foley J, Boulil Z, Van Dongen-Trimmer HM, Whalen D, Oluchukwu O, Liu KC, Burton J, Syngal P, Vargas-Shiraishi O, Kingsmore SF, Sanford Kobayashi E, Coufal NG.
Pediatr Crit Care Med. 2024 Apr 26. doi: 10.1097/PCC.0000000000003522. Online ahead of print.
ABSTRACT
OBJECTIVES: Analysis of the clinical utility of rapid whole-genome sequencing (rWGS) outside of the neonatal period is lacking. We describe the use of rWGS in PICU and cardiovascular ICU (CICU) patients across four institutions.
DESIGN: Ambidirectional multisite cohort study.
SETTING: Four tertiary children’s hospitals.
PATIENTS: Children 0-18 years old in the PICU or CICU who underwent rWGS analysis, from May 2016 to June 2023.
INTERVENTIONS: None.
MEASUREMENTS AND MAIN RESULTS: A total of 133 patients underwent clinical, phenotype-driven rWGS analysis, 36 prospectively. A molecular diagnosis was identified in 79 patients (59%). Median (interquartile range [IQR]) age was 6 months (IQR 1.2 mo-4.6 yr). Median time for return of preliminary results was 3 days (IQR 2-4). In 79 patients with a molecular diagnosis, there was a change in ICU management in 19 patients (24%); and some change in clinical management in 63 patients (80%). Nondiagnosis changed management in 5 of 54 patients (9%). The clinical specialty ordering rWGS did not affect diagnostic rate. Factors associated with greater odds ratio (OR [95% CI]; OR [95% CI]) of diagnosis included dysmorphic features (OR 10.9 [95% CI, 1.8-105]) and congenital heart disease (OR 4.2 [95% CI, 1.3-16.8]). Variables associated with greater odds of changes in management included obtaining a genetic diagnosis (OR 16.6 [95% CI, 5.5-62]) and a shorter time to genetic result (OR 0.8 [95% CI, 0.76-0.9]). Surveys of pediatric intensivists indicated that rWGS-enhanced clinical prognostication (p < 0.0001) and contributed to a decision to consult palliative care (p < 0.02).
CONCLUSIONS: In this 2016-2023 multiple-PICU/CICU cohort, we have shown that timely genetic diagnosis is feasible across institutions. Application of rWGS had a 59% (95% CI, 51-67%) rate of diagnostic yield and was associated with changes in critical care management and long-term patient management.
PMID:
38668387 | DOI:
10.1097/PCC.0000000000003522
April 26, 2024
RPM for NICU and PICUrWGS
Advancing access to genome sequencing for rare genetic disorders: recent progress and call to action
Jobanputra V, Schroeder B, Rehm HL, Shen W, Spiteri E, Nakouzi G, Taylor S, Marshall CR, Meng L, Kingsmore SF, Ellsworth K, Ashley E, Taft RJ; Medical Genome Initiative.
March 27, 2024
Rare Disease
The contribution of de novo coding mutations to meningomyelocele
Yoo-Jin Ha, Isaac Tang, Ashna Nisal, Ishani Jhamb, Cassidy Wallace, Sarah Schroeder, Chanjae Lee, Keng loi Vong, Naomi Meave, Fiza Jiwani, Chelsea Barrows, Sangmoon Lee, Nan Jiang, Arzoo Patel, Francisco A. Blanco, Seyoung Yu, Hui Su Jeong, Isaac Plutzer, Michael B. Major, Béatrice Benoit, Christian Poüs, Caleb Heffner, Zoha Kibar, Gyang Markus Bot, Hope Northrup, Kit Sing Au, Madison Strain, Allison Ashley-Koch, Richard H. Finnell, Joan T. Le, Hal Meltzer, Camila Araujo, Helio R. Machado, Roger E. Stevenson, Anna Yurrita, Sara Mumtaz, Osvaldo M. Mutchinick, José Ramón Medina-Bereciartu, Friedhelm Hildebrandt, Gia Melikishvili, Rony Marwan, Valeria Capra, Mahmoud M. Noureldeen, Aida M.S. Salem, Mahmoud Y. Issa, Maha S. Zaki, Ji Eun Lee, Anna Alkelai, Alan R. Shuldiner, Stephen F. Kingsmore, Stephen A. Murray, Heon Yung Gee, W. Todd Miller, Kimberley F. Tolias, John B. Wallingford, Spina Bifida Sequencing Consortium, Sangwoo Kim, Joseph G. Gleeson
medRxiv, March 2, 2024.
ABSTRACT
Meningomyelocele (MM) is considered a genetically complex disease resulting from failure of neural tube closure (NTD). Patients display neuromotor disability and frequent hydrocephalus requiring ventricular shunting. A few proposed genes contribute to disease susceptibility, but most risk remains unexplained. We postulated that de novo mutations (DNMs) under purifying selection contribute to MM risk. Here we recruited a cohort of 851 MM trios requiring shunting at birth, compared with 732 control trios, and found that de novo likely gene disrupting or damaging missense mutations occur in approximately 22.3% of subjects, 28% of which are estimated to contribute to disease risk. The 187 genes with damaging DNMs collectively define networks including actin cytoskeleton and microtubule-based processes, axon guidance, and histone modification. Gene validation demonstrates partial or complete loss of function, impaired signaling and defective neural tube closure in Xenopus embryos. Our results suggest DNMs make key contributions to MM risk, and highlight critical pathways required for neural tube closure in human embryogenesis.
DOI:10.1101/2024.02.28.24303390
March 2, 2024
Neurogenomics
Rapid genomic sequencing for genetic disease diagnosis and therapy in intensive care units: a review
Kingsmore SF, Nofsinger R, Ellsworth K.
NPJ Genom Med. 2024 Feb 27;9(1):17. doi: 10.1038/s41525-024-00404-0.
ABSTRACT
Single locus (Mendelian) diseases are a leading cause of childhood hospitalization, intensive care unit (ICU) admission, mortality, and healthcare cost. Rapid genome sequencing (RGS), ultra-rapid genome sequencing (URGS), and rapid exome sequencing (RES) are diagnostic tests for genetic diseases for ICU patients. In 44 studies of children in ICUs with diseases of unknown etiology, 37% received a genetic diagnosis, 26% had consequent changes in management, and net healthcare costs were reduced by $14,265 per child tested by URGS, RGS, or RES. URGS outperformed RGS and RES with faster time to diagnosis, and higher rate of diagnosis and clinical utility. Diagnostic and clinical outcomes will improve as methods evolve, costs decrease, and testing is implemented within precision medicine delivery systems attuned to ICU needs. URGS, RGS, and RES are currently performed in <5% of the ~200,000 children likely to benefit annually due to lack of payor coverage, inadequate reimbursement, hospital policies, hospitalist unfamiliarity, under-recognition of possible genetic diseases, and current formatting as tests rather than as a rapid precision medicine delivery system. The gap between actual and optimal outcomes in children in ICUs is currently increasing since expanded use of URGS, RGS, and RES lags growth in those likely to benefit through new therapies. There is sufficient evidence to conclude that URGS, RGS, or RES should be considered in all children with diseases of uncertain etiology at ICU admission. Minimally, diagnostic URGS, RGS, or RES should be ordered early during admissions of critically ill infants and children with suspected genetic diseases.
PMID:
38413639 | DOI:
10.1038/s41525-024-00404-0
February 27, 2024
RPM for NICU and PICUrWGSrWGS Efficacy
Evidence review and considerations for use of first line genome sequencing to diagnose rare genetic disorders
Wigby KM, Brockman D, Costain G, Hale C, Taylor SL, Belmont J, Bick D, Dimmock D, Fernbach S, Greally J, Jobanputra V, Kulkarni S, Spiteri E, Taft RJ.
NPJ Genom Med. 2024 Feb 26;9(1):15. doi: 10.1038/s41525-024-00396-x.
ABSTRACT
Early use of genome sequencing (GS) in the diagnostic odyssey can reduce suffering and improve care, but questions remain about which patient populations are most amenable to GS as a first-line diagnostic test. To address this, the Medical Genome Initiative conducted a literature review to identify appropriate clinical indications for GS. Studies published from January 2011 to August 2022 that reported on the diagnostic yield (DY) or clinical utility of GS were included. An exploratory meta-analysis using a random effects model evaluated DY based on cohort size and diagnosed cases per cohort. Seventy-one studies met inclusion criteria, comprising over 13,000 patients who received GS in one of the following settings: hospitalized pediatric patients, pediatric outpatients, adult outpatients, or mixed. GS was the first-line test in 38% (27/71). The unweighted mean DY of first-line GS was 45% (12-73%), 33% (6-86%) in cohorts with prior genetic testing, and 33% (9-60%) in exome-negative cohorts. Clinical utility was reported in 81% of first-line GS studies in hospitalized pediatric patients. Changes in management varied by cohort and underlying molecular diagnosis (24-100%). To develop evidence-informed points to consider, the quality of all 71 studies was assessed using modified American College of Radiology (ACR) criteria, with five core points to consider developed, including recommendations for use of GS in the N/PICU, in lieu of sequential testing and when disorders with substantial allelic heterogeneity are suspected. Future large and controlled studies in the pediatric and adult populations may support further refinement of these recommendations.
PMID:
38409289 | DOI:
10.1038/s41525-024-00396-x
February 26, 2024
Rare DiseaseRPM for NICU and PICU
